Robinia is a perennial deciduous tree from the legume family. Its openwork foliage and fragrant inflorescences resemble Mediterranean vegetation. Often robinia can be found under the name pseudoacacia or pseudoacacia. The plants are really similar, but it is robinia that blooms in white flowers. It is she who survives in central Russia and more southern regions. The birthplace of robinia is North America. The plant actively grows almost without care and does not require much effort.
Botanical Description
Robinia is a sprawling shrub up to 4 m high or a large tree. In the natural environment, its height can be 20-25 m, and in rare cases up to 35 m. A strong trunk often branches from the very base, forming several trunks. It is covered with cracking light gray bark. The height of garden plants is usually about 5 m. Robinia has a developed rhizome, which contributes to resistance to the wind and strengthens the soil.
In late spring, leafless buds form petiole leafless leaves. They have oblong bare or pubescent lobes with a shiny bright green surface. Leaflets are opposite. The length of the leaf along with the petiole is 25 cm. On some varieties, at the base of the petiole there is a short, but very sharp spike. The leaves, together with thin branches, form an openwork translucent crown.
In June, the flowering season of robinia begins. Large panicle inflorescences on flexible peduncles bloom in the axils of the leaves on young shoots. Snow-white or pink fragrant flowers have a moth shape. The bell-shaped calyx consists of 5 wide teeth. The upper pair grows together and forms a sail. The size of the inflorescence can reach 20 cm.
By the end of September, the first fruits ripen - brownish flattened beans. Their length is 5-12 cm. The bicuspid fruit contains several flattened brown seeds covered with a dense smooth skin.
Types of Robinia
The small genus of robinia has about 10 species. The most popular of them:
Robinia vulgaris (pseudoacacia). The plant lives on calcareous soils near the sea. It is a deciduous shrub or tree. A translucent crown with openwork leaves forms several umbrella tiers. The trunk is covered with bark, painted in a dark gray color. It has long, deep cracks. In spring, foliage is covered with silky pubescence, by summer it becomes smooth, dark green, and in the fall it acquires a golden hue. Fragrant drooping inflorescences bloom in June and last up to 20 days. Most often they are painted white. In October, dark brown beans 5-12 cm long ripen. Popular varieties:
- Pendula - with drooping branches;
- Rehderi - with a spherical crown;
- Tortuoza - meandering branches form a wide, flat crown;
- Argenteo-variegata - a plant with variegated leaves;
- Decaisneana - Blossoms pale pink inflorescences.
Robinia is sticky. A tree-shaped plant with a spreading, spherical crown grows 8-12 m in height. On young shoots, the bark is painted in a dark brown, slightly pinkish tint. Thick sticky pubescence covers the base of the petioles and inflorescences. Spines are practically absent. On each petiole, there are 13–25 lobes painted bright green. Their size is 17-20 cm. In June, large pink-violet or pink flowers that have no smell bloom on the tree. They are in compact upright brushes. Beans 5-8 cm long are also covered with bristly, sticky pubescence. The popular variety bellarosea - pink robinia - is distinguished by large dark pink inflorescences.
Robinia is bristly-haired. This shrub grows up to 3 m in height. He prefers Southern regions and does not tolerate frosts. The stems, leaves and petioles are covered with a long reddish pile or bristles. There are no thorns on the shoots. The branches are covered with a reddish-brown bark. Foliage about 23 cm long consists of oblong leaves of dark green color. At the beginning of June, drooping loose inflorescences of purplish pink or light pink blossom. Corolla length is 25 mm. In the inflorescence, they can be 3-9 pieces. In September, repeated flowering is possible. The bristle-glandular fruits ripen in October, their length is 8 cm.
Breeding methods
Robinia is propagated by seeds and root processes.
The seeds of the common robinia sprout best. For the beans to hatch sooner, they need specific preparation. Before planting, they are dipped in boiling water for several seconds, and then immediately immersed in ice water. As a result of this procedure, the outer shell is damaged and water penetrates the embryo. You can also carry out scarification, that is, treat the bean skin with a file. Seeds are first planted for seedlings in a greenhouse or containers with a sand-peat mixture. Do it in early May. In order for seedlings to appear, the soil temperature must be + 20 ... + 23 ° C. Shoots appear within 2 weeks. They are grown without shelter and regularly watered. In the summer, pots with seedlings are transferred to the garden, where they leave until next spring. Year-old plants can be transplanted to a permanent place.
When propagating robinia by a vegetative method, basal shoots are more often used. An adult plant gives several shoots annually; it is enough to dig them out and transplant them to a new place. Some gardeners form air layers. To do this, you need to fix the tank with the ground on a branch. Over the summer, roots grow in the soil. The rooted branch is sawn off from the mother tree and planted in a permanent place.
Plant care
Robinia is considered an unpretentious plant, so it does not require much effort. The plant is quite undemanding to the soil and can adapt to any composition of the earth. However, trees develop best on loam with the addition of lime. The landing site should be sunny and open. It is advisable to provide protection against cold gusts of wind.
Young robinias are more sensitive to frost, so the plants cover and protect the trunk with a non-woven material for the winter. Mature trees can withstand frosts down to -35 ° C. Those specimens that are planted in dense and moist soils are more affected. After planting, it is recommended to mulch the soil surface with sawdust or peat to a height of 4-6 cm. This will save the plants from weeds and the formation of a dense crust after watering.
Robinia loves moist soils, but without stagnation of water. Mature trees can withstand severe drought, so they will have to be watered extremely rarely. In most cases, plants get by with natural rainfall.
All varieties need organic top dressing. It is best to use rotted manure. On depleted soils, fertilizing is recommended monthly.
The plant normally tolerates pruning and shaping of the crown. It is best to carry out the procedure in early spring. After the leaves open, re-pruning is carried out, removing dry branches. It is also recommended to monitor the appearance of basal shoots and remove it in a timely manner. The developed rhizome of robinia spreads quite far, so the plant must be limited.
Robinia is practically not affected by plant diseases and parasites, so you do not have to take care of pest protection. This, of course, is one of the advantages of pseudo-activation.
Using
Robinia is a highly decorative culture. It has a light openwork crown, which during the summer can be covered several times with fragrant flowers. It is important to be careful, because robinia can be aggressive towards other fruit trees and shrubs. It should be planted at a distance from them. Group plantings can be found in park alleys, in gardens and near houses.
Robinia flowers and its bark are used in folk medicine as an astringent, expectorant, antipyretic and anti-inflammatory agent. Raw materials are brewed to combat diseases of the gastrointestinal tract, as well as rheumatism, urolithiasis and neuralgia.
In the flowering period, robinia is a good honey plant. Honey from it has a light shade and high transparency, it also does not sugar for a long time and has a delicate, pleasant aroma.
The wood of the plant is famous for its high mechanical properties and density. Piles, poles and other carpentry are made from it.
